Offshore Marine Forecasts are Vital
** Affiliate disclosure. This web site is supported by its awesome audience. When you click or purchase through links on our site, we may earn an affiliate commission.

Offshore marine forecasts are vital for navigating the seas. The NOAA weather buoys provide real-time sea conditions. This allows you to make better decisions on where to go and when to leave. It is advisable to check all of the forecasts available before heading out to sea. This will ensure that you are safe and have the best possible chance of getting to where you need to go.
Coastal Waters and Local Waters forecast
The Coastal Waters and Local Waters forecast is issued twice daily, usually at 5am and 5pm, and covers three to four days. The forecasts include a predicted tide and buoy observations. The forecasts are updated at regular intervals, including when a wind warning is issued.
Coastal waters forecasts are based on marine radio broadcasts. The Coastal Waters and Local Waters forecast is intended to give skippers a general idea of conditions for boating. Although the forecasts show average winds and sea conditions, you should be prepared for local effects. For example, maximum waves may reach twice as high, and wind gusts can be up to 40 percent stronger.
Coastal Waters and ESTOFS
The Extratropical Storm Surge and Tide Operational Forecast System (ESTOFS) is a computer model developed by NOAA. It predicts the combined water level that is caused by extratropical storm surge and tides. The system uses an unstructured grid and a coastal resolution of three kilometers. It uses sea level pressure and winds to produce predictions out to 180 hours.
For marine weather forecasts, check the National Weather Service’s marine weather page. The NWS marine forecast covers California’s Central Coast, Monterey Bay, and the San Francisco Bay. It also covers the offshore waters of New England and the Caribbean. The forecasts are also available in text format.
ESTOFS was developed to serve the needs of the National Centers for Environmental Prediction/Ocean Prediction Center and the National Hurricane Center/Tropical Analysis and Forecast Branch and the Weather Forecast Offices for coastal inundation forecasts. The ESTOFS has undergone thorough statistical skill assessment and hindcast tests. It was operationalized by NCEP in August 2012.
Coastal Waters and Navtex
Offshore marine forecasts from Coastal Waters and Navtex are available for the UK and its offshore waters. This information is issued by the Met Office, which initiates warnings and routine forecasts. These forecasts are published four times a day and are updated every 15 minutes. Coastal Waters is the UK’s coastal waters, which extend up to 12 nautical miles offshore.
The forecasts are also available in synopsis form. The synopsis summarizes the conditions for coastal and offshore waters, seas, and precipitation. It also highlights the movement of high pressure systems and fronts. The synopsis is shorter than the high seas forecast and has a wider range of information.
Coastal Waters and Navtex offshore maritime forecasts were first broadcast in 1985 via a coastal radio station in Lands End, and the service soon expanded to include marine warnings for the Irish Sea and the South-west Approaches. It was then relocated to BT International’s coastal radio station in 1986.
Coastal Waters and Navtex offshore maritime forecasts provide important information for offshore sailors. For small craft owners, Frank Singleton’s site contains additional information and links to other useful sites. If you don’t want to pay for a subscription to either, there is a simple way to get the data you need from both Navtex and Coastal Waters.
While these offshore marine forecasts are highly useful, they’re not complete. A strong land breeze or strong current can alter a marine forecast. A strong current may cause waves to increase in height.
Radiofax
Radiofax offshore marine forecasts can be a lifeline for mariners. These forecasts are updated at different times of the day, seven days a week. On a standard weekday, the service provides marine weather forecasts at 00:48 and 05:36 local time. They also provide reports from coastal stations. The files are very small, which means that mariners can download them in a matter of seconds.
The USCG produces and transmits these charts for free. They are created by seasoned oceanographic meteorologists and are updated four times a day. The charts are available for free via multiple channels and transmitter locations. You can subscribe to these free marine forecasts on any marine radio station. For those who live in Spanish-speaking countries, the website also offers links to the charts and text forecasts.
Marine VHF radios have been used to receive marine weather information near shore for decades. They provide marine forecasts, severe weather advisories, and audio reports of local conditions. SSB/weatherfax systems are typically more comprehensive and provide long-range reports and graphic displays of weather maps. These systems are available globally and can be used to monitor marine weather conditions at sea.
The National Hurricane Center (NHC) and Ocean Prediction Center (OPC) also provide marine weather forecasts. Besides offering weather reports and marine weather maps, they also provide information on weather and sea conditions for coastal and great lakes waters. However, their coverage is limited and their reliability is lacking.
Cape Cod area & offshore marine forecasts
The Cape Cod area and offshore marine forecasts cover the waters off the coast of New England, Nantucket Sound, Great South Channel, and Georges Bank. If you plan to sail in these waters, it’s important to check the forecast before setting sail. When the Cape Cod area is prone to storms, you may want to consider taking an alternate route.
This area experiences considerable coastal erosion, which could cause the entire Cape to be covered by the ocean within several thousand years. This erosion process washes away beaches and destroys barrier islands. At one point, the ocean smashed through a barrier island near Chatham, allowing waves to hit the coast unhindered. Meanwhile, the sand and sediment from the beaches is being washed inland and deposited in marshes.
Hurricanes and tropical storms can cause high winds, heavy rain, and storm surges. Since record-keeping began, several Category 3 storms have hit Cape Cod. The 1869 Saxby Gale and the 1938 New England hurricane caused considerable damage to the area. In addition, Hurricane Edna and Hurricane Bob both caused extensive damage to the area.
In summer, southwest breezes are the norm. Often, the wind force begins slowly and builds throughout the day. This can make sailing on the south side of Cape Cod uncomfortable for small boats. Buzzards Bay, Nantucket Sound, and Vineyard Sounds are all known to be windy, and they may make a trip in a small boat a difficult proposition. For the best coastal navigation, Cape Cod area marine forecasts are an essential tool. Despite its geographic isolation, the peninsula is connected to the mainland by a pair of highway bridges, the Bourne Bridge to the west and the Sagamore Bridge to the east. These bridges form a bottleneck and traffic backups can exceed several miles during peak tourist season.

Rick is the head writer at MaydayMarine.com Rick creates product review and ranking content in the maritime industry. His focus is mainly on safety offshore at MayDayMarine.com